Drill pipe float valve



May 27, 1969 W. L. HALEY Filed April 3, 1967 IOb I00 ,0 [Up a V 40 I300 [0 42- i i V/ 28a 30b 24 2a 35 26 20c I0 Fl .3 20

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J .L N] i IOg WILLIAM L. HALEY 1 N VEN TOR.

61 Fwd A T TORNE Y8 United States Patent US. Cl. 137-463 3 Claims ABSTRACT OF THE DISCLOSURE A float valve for use with drill pipe in a well wherein the valve is maintained in an open position while lowering the pipe in the well to thereby automatically fill the pipe with drilling mud or fluid, and wherein such valve is adapted to be closed with pressure fluid which is under the control of an operator at the surface of the well for effecting a subsequent floating of the drill pipe or for closing the drill pipe due to an incipient blowout or for any other reason.

Background of the invention The field of the present invention is the well drilling art. It is well known that during the lowering of drill pipe into a well having drilling fluid therein it has been necessary to frequently stop and fill the pipe with fluid, using a conventional float valve. Examples of such prior float valves are shown in United States Patent Nos. 3,058,534 and 2,162,578. Not only is such stopping and filling undesirable from the standpoint of loss of valuable and expensive rig time, but the filling of the drill pipe with drilling mud or fluid introduces an element of danger to personnel since such mud is generally very slick or slippery when spilled on the derrick floor. Additionally, kelly-cut drilling fluid, which is fluid having air entrapped therein during the filling of the :drill pipe, is often produced using the prior art float valves. The presence of such air in the mud reduces its density and hydrostatic head so that danger of a blowout is increased.

Summary of the invention The present invention overcomes the problems of the prior art float valves in that it is unnecessary to stop the drill pipe to fill same when lowing, thereby saving valuable rig time and expense. Furthermore, with the present invention, the float valve is held open so that the drill pipe is filled by the flow of fluid thereinto from the well casing, thereby avoiding the danger [which might result from spilling drilling mud on the derrick floor and also avoiding the further danger of Kelly-cut mud.

While providing the foregoing advantages the float valve of the present invention has the additional feature of being movable to a closed position by fluid action through the drill pipe when such closing becomes desirable for floating the drill pipe or for any other reason.

Thus, the object of the present invention is to provide a new and improved float valve which may be operated from the surface of the well without special tools and which provides for filling of the drill pipe Without the loss of time and dangers encountered when using prior float valves.

Brief description of the drawing The preferred embodiment of this invention will be described hereinafter, together with other features thereof, and additional objects will become evident from such description.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof wherein an example of the invention is shown and where 1n:

FIG. 1 is an elevation of the float valve of the present invention;

FIG. 2 is a sectional view taken on line 2-2 and showing further details of the float valve of FIG. 1; and

FIG. 3 is a view similar to FIG. 2, but illustrating a modified form of the float valve of FIG. 1.

Description of the preferred embodiments In the drawings, the letter F designates the preferred embodiment of the float valve of the present invention. The float valve F is mounted near the lower end of a string of drill pipe in any conventional manner and is normally in an adapter sub just above the drill bit. One example of a means for mounting a float valve is disclosed in said United States Patent No. 3,058,534, and such mounting arrangement may be used for mounting the float valve F of the present invention.

The float valve F has a body 10 which is generally cylindrical and which has a longitudinal bore 1001 (FIG. 2) extending completely therethrough from its upper end 10b to a lower shoulder 10c. Below the shoulder 100, the body 10 is formed with windows 10a on diametrically opposite sides from each other, leaving only longitudinal body legs 10e which connect with the lower base 10 of the body 10. The base 10, has a lower annular surface 10g which is adapted to be positioned on any suitable support within a mounting sub of a drill pipe as will be well understood. The bore 1011 of the base 10) is aligned with and is preferably of substantially the same diameter as the bore 10a so that fluid may flow through the entire body 10 in either direction when the valve is in the open position as will be more fully explained.

The upper portion of the body 10 has a sealing assembly which includes an upper lip seal 12 formed of rubber or other resilient material and having an exposed annular lip 12a which is adapted to engage the inside surface of a drill pipe adapter sub or other supporting body so as to prevent fluid from flowing downwardly around the exterior of the body 10. The sealing assembly also includes a lower lip seal 14 of rubber or other resilient material having an annular lower lip 14a which similarly engages the inside surface of a drill pipe adapter sub for preventing the flow of drilling mud or fluid upwardly around the exterior of the body 10.

To further assist in such sealing action, the sealing as sembly has an Oring 16 formed of rubber or similar resilient material disposed between the lip seals 12 and 14 for similar engagement with the inner surface of the drill pipe adapter sub or other support in which the float valve F is mounted. It is to be noted that the upper end of the body 10 is formed with locator notches 10k which may be used for locating and positioning well survey instruments as will be well understood.

The float valve F has a flapper valve 20 which is preferably formed in a generally circular configuration with a generally planar or flat upper surface 20a which is adapted to engage the lower annular edge or surface of the body 10 for closing the longitudinal opening 100 when desired. The surface 10:: may be formed of metal so that a metal to metal seal is provided with the lower metal surface 100; if desired, rubber or other resilient sealing material may be employed as a gasket in any conventional way to provide additional sealing between the surfaces 2001 and 100. The lower surface 20b of the flapper valve 20 is connected to a pivot arm 22 by welding same at the junction 22a therebetween, or by the use of any other suitable attaching means. The arm 22 is disposed between two hanger lugs 24 which are formed integrally with, or are secured to, the body 10. Such hanger lugs 24 are provided with suitable openings for receiving a pivot pin 26 therethrough. The pivot pin 26 also extends through a suitable opening in the pivot head end 2% of the pivot arm 22 so that the arm 22 is adapted to pivot with respect to the pivot pin 25 for thereby pivoting the flapper valve 20 with respect to the body 10, as will be more evident hereinafter.

A coil spring 28 surrounds the central portion of the pivot pin 26 (FIGS. 1 and 2) and is wound under tension thereon with one end 28a suitably disposed in a notched recess m: of the body 10 while the other end 26b is in engagement with the lower surface 100 so that such spring 28 constantly acts to urge the flapper valve into a closed position with the upper surface 20a in engagement with the annular lower surface or edge 100. Such spring 28 is illustrated only by way of example since other resilient means may be employed for normally urging the flapper valve 20 to the closed position while permitting it to be moved to the open position of FIG. 2.

An important feature of the present invention is a swing check means which includes an elongate element 30 for holding the flapper valve 20 in its open position until it is desired to close same, as will be explained. The elongate element 30 may have different shapes and configuration, but it is preferably a relatively thin member which has adequate strength for overcoming the resilient force of the spring 28 which is tending to push the flapper valve 20 in a clockwise direction as viewed in FIG. 2. The upper surface 20a of the flapper valve 20 is preferably provided with a notch 200 for receiving the lower end of the elongate check element 30. The upper end of the elongate element 60 is preferably thicker than the lower end for adequate strength, although this is not essential if the material of the elongate element 30 is adequate for holding the flapper valve 30 in the open position as illustrated in FIG. 2. The upper end of the elongate element 30 is disposed between depending brackets or lugs 35 which are formed integrally with or are secured to the lower surface 100 of the body 10. A suitable pivot pin 36 extends through the lugs 35 and the upper end of the elongate element 30 for permitting pivotal movement of the elongate element 30 relative to the lugs 35 and the body 10.

In normal usage, the elongate element 30 assumes two positions, the first being an inclined position as shown in FIG. 2 wherein the lower end of the element 30 is in the notch 200 for holding the flapper valve 20 in the open position. To facilitate the holding of the elongate element 30 in such position, a coil spring 40 is disposed in a recess 10pof the body 10. The upper end of the spring 40 is preferably welded or otherwise secured to the body 10 within the recess 10p while the lower end is Welded or is otherwise secured to a ball 42 which is adapted to fit within a notch or detent 30a when the elongate element :30 is in the first or inclined position of FIG. 2. When the element v30 has been moved to its second position, wherein it is substantially vertical, by fluid pressure acting downwarlly thereon, as will be more fully explained, the element 30 is locked in such second or released position by the engagement of the ball 42 in a second notch or detent 30b. The element 30 is thus held in its relased position by the action of the spring holding the ball 42 in the detent 3% until the element 30 is manually reset at a later time to the inclined position shown in FIG. 2.

To effect a movement of the elongate element 30 from its holding position illustrated in FIG. 2 to its released position, a target 50 is welded or is otherwise secured to the upper surface of the elongate element 30. Such target 50 provides a relatively large surface area which is in the direct line of flow of fluid flowing downwardly through the body 10a of the float valve F. Therefore, when a predetermined amount of fluid pressure is forced downwardly with an adequate force, it moves the elongate element 30 in a clock-wise direction as viewed in FIG. 2 to release the lower end of the elongate element from the notch 20c and to thereby move the element 30 away from the flapper valve 20. It will be appreciated that as soon as the lower end of the element 30 has moved away from the flapper valve 20- so as to permit the valve 20 to pass above the element 30, the spring action of the spring 28 will urge the flapper valve 20 upwardly to the closed position.

In the operation or use of the float valve F of the present invention, it is lowered into a well casing having drilling mud or other fluid therein and is disposed in a drill pipe in the usual manner as previously explained. The flapper valve 20 is held in the fully open position shown in FIG. 2 so that the drilling mud or other fluid in the well may flow upwardly into the drill pipe as the drill pipe is lowered. Thus, the drill pipe is automatically filled with the drilling mud or fluid as it is lowered without any necessity for stopping such lowering to accomplish the filling. It is to be noted that the flow of the mud upwardly into the drill pipe acts in a direction which assists in maintaining the elongate element 30 in the notch 200 so as to maintain the flapper valve 20 in the open position during the lowering operation.

When the drill pipe has been lowered a suflicient distance in the well so that it becomes desirable to thereafter float the drill pipe further downwardly into the well, fluid pressure may be introduced through the drill pipe from the surface so that a downward fluid force is exerted on the target 50' and thereby on the element :30 to move same in a direction clockwise as viewed in FIG. 2 for moving the lower end of the element 30 out the notch 20c, to thereby relase the flapper valve 20 for clockwise movement by the urging of the spring 28 to its closed position. The element 30 moves to its released position and is held there by the action of the ball 42 in the detent 30b, as previously explained. Thereafter, the drill pipe may be continued in its lowering in the well with the flapper valve 20 closed but capable of being opened if desired in the known manner.

In some instances, an incipient blowout develops as indicated by a kick of gas at the well surface, and it is desirable to close the flapper valve 20 to avoid a blowout. Therefore, the flapper valve 20 may be closed for preventing a blowout or for any other reason in addition to the floating purpose. It can thus be apreciated that the flapper valve 20 of the present invention is maintained in the open position until such time as the operator desires it to be closed, and thereafter the flapper valve is capable of operating in the conventional manner without any obstruction or restriction. The flapper valve 20 remains in the closed position once it has been released until it has been later manually reset at the surface of the well.

Instead of using the target 50 on the elongate element 30, the surface 20a of the flapper valve 20 may itself be used for target for the downward fluid force, in which case the flapper valve 20 is positioned at an angle to the longitudinal axis of the bore 10a. One manner in which this may be accomplished is illustrated in the modified form of the invention of FIG. 3. In FIG. 3, all of the structure is identical to that of FIGS. 1 and 2 except that a modified elongate element is provided in place of the elongate element 30 of FIG. 2, and it is mounted diflerently as will be explained. Therefore, the parts in FIG. 3 which are identical to those in FIGS. 1 and 2 bear like numeral and letter designations.

It is to be noted that the target area for the downward fluid force is provided by the upper surface 20a of the flapper valve 20 in FIG. 3.

The modified elongate element 130 is in the form of a steel wire or strip of metal which is resilient and is mounted with its upper end welded or otherwise secured at 130a to the body 10. The lower end 1301) of the elongate element 130 is adapted to extend into the notch 200 of the flapper valve 20 so as to prevent the flapper valve 20 from being urged to the closed position by the spring 28 until the elongate element 130 has moved out of the notch 20c to a substantially vertical position. The inherent resiliency of the steel or other metal forming the elongate element or wire 130 normally holds it in a substantially vertical position, and it is bent to an inclined position as shown in FIG. 3 to position it in the notch 200 for holding the flapper valve 20 in the open position. However, as soon as the downward fluid force acting on the surface 20a is suflicient to move the flapper valve 20 slightly to the right or counterclockwise as viewed in FIG. 3, the lower end 13% of the element 130 is moved out of the notch 200 by the inherent resiliency of the elongate element or wire 130 so that thereafter the flapper valve 120 is moved to its closed position by the spring 28.

It will be appreciated that the resilient wire or other element 130 may have a target such as the target 50 employed therewith if desired so that it is the object which is encountered by the downward fluid force rather than the surface 20a. In some instances, both the surface 20a and a target such as the target 50 on the elongate element 30 or 130 may be employed for the elfecting of a release of the holding of the flapper valve 20 in the open position. The elongate element 130 requires a manual resetting after it has been moved to its substantially vertical released position, and it is to be noted that it is out of the way of the bore a so that the flapper valve may function in the normal manner without interference from the element 130 after the flapper valve 20 has moved its closed position.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in the details of the illustrated construction may be made within the scope of the appended claims without departing from the spirit of the invention.

I claim:

1. A float valve for use with a drill pipe comprising:

(a) a valve body with a longitudinal bore therethrough;

(b) a flapper valve resiliently mounted on the valve body for swinging from an open position wherein said bore is open for the flow of fluid therethrough to a closed position wherein said bore is closed for preventing the inflow of fluid into said bore from the well, said flapper valve having a notch in its surface which is uppermost when the flapper valve is in the closed position;

(c) a catch means including an elongate member having a first end and a second end, said first end being positioned in said notch when second valve is in said open position; and

(d) catch mount means mounting said catch means for movement out of holding engagement with said flapper valve upon the application of a predetermined downward fluid force whereby said flapper valve is urged to said closed position, said catch mount means being disposed substantially diametrically opposite from said flapper valve for securing said second end of said elongate member pivotally thereto for swinging movement of said elongate member from an inclined holding position to a substantially vertical release position when said flapper valve is urged to said closed position.

2. The structure set forth in claim 1 wherein said catch mount means includes:

(1) pivotal means mounting said elongate element for pivoting from said notch to release said flapper valve;

(2) resilient locking assembly supported by said body said resilient locking assembly including a spring means and a ball means, said ball means being urged continuously outwardly toward said second end of said elongate element; and

(3) a detent in said second end of said elongate element for engagement by said ball means to hold said element in said released position.

3. The structure set forth in claim 2, wherein:

(a) said catch means includes a target mounted therewith for providing a relatively large surface area to be contacted by fluid pressure from said bore of said body to release said catch means from holding said flapper valve.

References Cited UNITED STATES PATENTS 2,587,358 2/1952 McRae 137463 2,694,408 11/1954 McRae 137-463 XR 2,973,006 2/1961 Nelson 166-225 XR 3,013,612 12/1961 Angel 166-225 HAROL'D W. WEAKLEY, Primary Examiner.

US. Cl. X.R.

137515.7, 527, 523; l66225; l3l8 

